A vibration-type angular velocity sensor serves as a sensor for measuring the magnitude of the angular velocity by causing a vibrator to vibrate at a predetermined frequency in a prescribed vibration direction, thereby generating Coriolis force in accordance with the angular velocity acting from the outside, and detecting the displacement amount of the vibrator caused by the Coriolis force in the direction orthogonal to the vibration direction. The vibrator is supported by a spring structure or the like, and the Coriolis force is increased in proportion to the vibration velocity of the vibrator. In order to improve the sensitivity of the angular velocity sensor, it is necessary to increase the vibration amplitude of the vibrator in the vibration direction to increase its vibration velocity. Thus, the above-described angular velocity sensor generally serves to detect the vibration amplitude of the vibrator and apply positive feedback with a drive signal for driving the vibrator, thereby causing the vibrator to self-excite at a resonance frequency (see, for example, PTD 1).
Among the conventional angular velocity sensors, there is a known angular velocity sensor that is equipped with a plurality of vibrators for measuring the tri-axial angular velocity (see, for example, PTD 2). In general, when a plurality of vibrators are mounted in an angular velocity sensor, the resonance frequencies of the vibrators are varied. Accordingly, a drive circuit for causing the vibrators to self-oscillate should be provided for each of the vibrators. This poses a problem that the drive circuit is increased in circuit scale, and power consumption. Furthermore, in the case where the plurality of vibrators are caused to self-oscillate at different resonance frequencies, it becomes necessary to separately generate synchronous detection signals synchronized with the corresponding resonance frequencies of the vibrators in order to synchronously detect the vibrating component of the Coriolis force. This also poses a problem that not only the drive circuit but also the control circuit for synchronously detecting the vibrating component of the Coriolis force is increased in circuit scale, so that power consumption is also increased. In order to solve the above-described problems, according to the conventional technique disclosed in PTD 2, a plurality of vibrators are coupled structurally dynamically to cause the resonance frequencies of the vibrators to coincide, so that drive circuits for driving a plurality of vibrators are implemented by a single circuit.